The Properties of Cu Thin Films on Ru Depending on the ALD Temperature

The copper thin films were deposited by Atomic layer deposition (ALD) on a ruthenium depending on the substrate temperatures. The substrate deposited Ru and TaN on SiO2 by plasma enhanced ALD (PEALD) before Cu deposition for an adhesion layer between Si and Cu. The copper thin films were deposited 200 cycles. The thickness of Cu was different depending on the substrate temperatures. The properties of copper thin films were investigated by a 4 point probe, SEM, and AFM. TaN and Ru layers were deposited by plasma enhanced ALD (PEALD) for the adhesion layer. Also, TaN and Ru layers were observed as TEM because the thickness was too thin. The thickness and roughness of Cu thin film increased depending on the deposition temperatures but, Cu thin film was not deposited at 110 °C. The best sheet resistance of the copper thin film was obtained at a deposition temperature of 170 °C.